ML20197G085

Forwards Addl Input for Sser 4 Re Overheating of Gadolinia Fuel,Supplementing 830414 Memo.Issue Resolved

ML20197G085
Person / Time
Site:	Columbia
Issue date:	11/23/1983
From:	Rubenstein L Office of Nuclear Reactor Regulation
To:	Novak T Office of Nuclear Reactor Regulation
References
CON-WNP-0689, CON-WNP-689 NUDOCS 8312060396
Download: ML20197G085 (2)

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'NOV 2 31983 DISTRIBUTION:

MEMORANDUM FOR: T. M. Novak, Assistant Director L. Rubenstein ..

for Licensing, DL C. Berlinger J. Voglewede FROM: L. S. Rubenstein Assistant Director for Core and Plant Systems, DSI

SUBJECT:

ADDITIONAL INPUT FOR WNP-2 SER SUPPLEMENT NUMBER 4 Plant Name: Washington Public Power Supply System Nuclear Project No. 2 Docket Number: 50-397 Licensing Stage: Operating License Responsible Branch: Licensing Branch No. 2 Project Manager: R.Auluck(49-28547)

DSI Review Branch: Core Perfomance Branch DescMption of Review: Supplemental Safety Evaluation Review Status: Complete The Reactor Fuels Section of the Core Performance Branch has prepared

, the enclosed additional input for WNP-2 SSER No. 4. This input, which supplements that previously transmitted to you by my memorandum of April 14,1983, concerns overheating of gadolinia fuel . Upon consider-ation of a recent submittal from WPPSS on this subject, and upon com-pletion of our review of General Electric's fuel thermal performance code (which may be applied to gado11nia fuel), we conclude that this issue has been resolved for WNP-2 and that no further infomation is required. The basis for this conclusion is discussed in the enclosure.

O.-!. :..cl aigne: by L.S.RubenstMn L. S. Rubenstein Assistant Director for Core and Plant Systems, DSI l

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Enclosure:

As stated cc: A. Schwencer R. Auluck _.

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Contact:

J. Voglewede. DSI:CPB X-29479 .

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4.2.3.2(d) Overheating of Fuel Pellets Fuel melting temperature is discussed in Section 2.4.2.5 of NEDE-24011 as a function of exposure (burnup) and gadolinia content (of burnable poison rods). In that report, General Electric stated that fuel melting is not expected to occur during normal operation, and that prediction is based on fuel temperature calculations performed with a model described in the proprietary supplement to Amendment 14 of GESSAR (STN 50-447).

While limited melting during certain events such as an uncontrolled control rod withdrawal is permissible, such melting is not predicted to occur.

We have reviewed the UO2 pr perties (thermal conductivity and melting point) that are important in reaching this conclusion and, as previously stated, we agree that UO2 melting will not be a problem at WNP-2 during normal operation and anticipated transients. At that time, however, we also noted that the effects of gadolinia concentration on thermal conductivity and melting temperature were addressed in an unreviewed GE topical report on gadolinia fuel properties (NEDE-20943). That report has been replaced by another topical report (NEDE-23785-1), which describes revised fuel thermal performance methods and (Appendix B) gadolinia properties. The more recent report has been reviewed and approved by the NRC staff.

The applicant has stated (G. C. Sorensen to A. Schwencer dated November 17, 1983) that gadolinia properties described in Appi.* dix B of NEDE-23785-1 are applicable to WNP-2 and that General Electric t..s confirmed that the applicable limits for overheating of gadolinia 'Nel remain valid. Because these limits were previously found acceptable. for WNP-2, and because the applicant has utilized approved methods (and gadolinia properties) to show that these limits continue to be met, we consider the issue resolved.

. November 25, 1933 Decket Nos.: 50-397 - I E'I and 50-374 MEMORANDUM FOR: H. Denton distribution E. Case .

J. Carter

• Document Control'(50-397/374)

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D. Eisenhut NRC PDR R. Purple PRC System H. Thompson LB#2 Reading R. Vollmer Attorney, OELD R. Mattson ASchwencer T. Spels ABournia J. Sniezek RAuluck G. Holahan .

T. Novak ng, F. Miraglia DL:'CH2 DL 2 A. Schwencer, Chief ABournia:ft ck ASchw neer THRU:

Licensing Branch No. 2 g /;s/83 ll /gg/83 4 /> 83 Division of Licensing FROM: R. Auluck, and A. Bournia, Project Managers Licensing Branch No. 2 Division of Licensing _

SUBJECT:

DAILY HIGHLIGHT - READINESS FOR FUEL LOADING AND LOW POWER OPERATION - LASALLE, UNIT 2 AND WNP-2 LaSalle, Unit 2 For the LaSalle, Unit 2 BWRS/ Mark II plan.t. construction is complete and the plant is expected to be ready for fuel loading in early December,1983. The NRC staff has scheduled a final operational readiness meeting.with the applicant, Comonwealth Edison ~ Company, in Behtesda, on November 30, 1983 to assure that all licensing prerequisites have been met to permit issuance of a full power license - conditioned to require further NRC approval before operating above 5%

power.

WNP-2 For the WNP-2 BWR5/ Mark II plant, construction is complete and the plant is expected to be ready for fuel loading by mid December,1983 The NRC staff has scheduled an operational readiness meeting with the Washington Public Power Supply System at the plant site on December 6, 1983 to assure that all licensing pre-requisites have been met to pennit issuance of a full power license - conditioned to require further NRC approval before operating above 5% power, A. Bournia, Project Manager R. Auluck, Project Manager Licensing Branch No. 2, DL Licensing Branch No. 2. DL cc: S. Black .k! - . -

DL BC's oNooN4 A .

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